Process for the preparation of monocyclic ketones and their alkyl derivatives havingmore than nine ring members



ring members,

o by starting Patented Feb. 19, 1929.

UNITED STATES PATENT OFFICE.

LEOPOLD.IB,UZIOKA, OF GENEVA, SWITZERLAND, ASSIGNOB TO M. NAIF & 00-, 0.0.

A COMPANY OF SWITZERLAND.

GENEVA, SWITZERLAND,

PROCESS IOR THE PREPARATION OF MONOGYCLIC KETONES AND THEIR ALKYL DE RIVATIVES HAVING MORE THAN NINE RING MEMBERS.

no Drawing. Application filed; November 19,

1926, Serial No. 149,543, and in Switzerland December In the prior application, Serial No. 36,049, filed June 9, 1925, now Patent No. 1,673,093, there is described a process for the formation of monocyclic ketones having more than nine according to which normal dicarboxylic acids having more than ten carbon atoms in a normal chain are subjected to the usual methods for preparing ketones. It has been found advantageous to use cerium for these methods. 7

It has since been discovered that according to these methods the alkyl derivatives of the above mentioned ketones can be obtained. This discovery forms the subject of the present invention.

According to the present invention alkyl derivatives of monocyclic ketones having more than nine ring members are prepare from the alkyl derivatives of the dicarboxylic acids having more than ten carbon atoms in a normal chain. The use of metals or compounds of metals belonging to the fourth group of the periodic system for instance cerium has also been found advantageous.

It is also advantageous to use a mixture of these metals or ofa mixture of two or more metals of the third and fourth groups 0 the periodic system or of the rare earths, these mixtures being obtained artificially or otherwise.

Mixtures of the above mentioned dicarboxylic acids or their alkyl derivatives, which are prepared from the pure acids, or their ones-coo a fume as Well as a primary material for pretained in certain technical processes or from natural products, give, according to the present invention, mixtures of the ketones ortheir alkyl derivatives, which, in this form, can also be employed in practice.

For obtaining the mentioned monocyclic ketones it is also possible to directly heat the acids or the acid anhydrides alone or in presenceof metals or metal compounds to a comparatively high temperature, instead of first transforming the corresponding dicarboxylic acids into salts. In this case the use of metals of the fourth group of the periodic system is also advantageous.

The ketones and their alkyl derivatives obtained by the described process can be used as perfumes or as primary materials for the preparatlon of other technically important compounds.

E mample 1.

f fractions distilling at from 100 to 150 C. at

a pressure of 0.5 mm. are then treated with semicarbazide or another of the reagents usually employed for isolating the ketones.

The formation of the 3-methyl-cyclopentadecanone can be represented by the following equation:

paring other interesting technical compounds.

Example 2.

3-methyl-tetradecane-LM-dicarboxylic acid is heated up to above 300 to 500 degrees centigrade and towards the end of the reaction preferably in a vacuum with cerium hydroxide in a quantity which does not suifice for completely converting the acid into the normal salt. The product obtained is treated according to the method described in 'Example 1.

Ewample 5.

A mixture of cerium, didymium and lanthanum salts of 4-inethyl-tetradecane-1.14- dicarbox lic acid is heated and worked up as descri ed in Example 1.. The 4-methylcyclopentadecanone obtained boils at about 125 C. (at 0.3 mm), gives a semicarbazone melting at about 166 C. and has a smell practically corresponding completely to that of natural musk and can therefore be used as perfume and for preparing other interesting technical compounds EmampZe 4.

l-methyl-tetradecane-1.l l-dicarboxylic acid is heated at about 300 to 500 C. and towards the end of the reaction preferably in a vacuum, with cerium oxide, The product obtained is worked up as described in Ex ample 3.

' Ema maple 5.

A cerium salt of tetradecane-Lld-dicarboxylic acid Y is prepared by partially neutralizing this acid with sodiumhydroxide and precipitating with cerium chloride. The resulting cerium salt is decomposed by heating and worked up as described in Example 1.

Ewample 160 C. (at 0.3 mm.), melts at 72 C. and has a smell which nearly corresponds to that of civetone. It can therefore be used as a perfume and as first matter for preparing other interesting technical compounds; by oxidizing the cyclononadecanone with chromic acid heptadecane-1.17-dicarboxylic acid isformed.

I claim:

1. A process for the preparation of alkyl derivatives of monocyclic ketones having more than nine ring members comprising heating salts of a metal belonging to the fourth group of the periodic system of alkyl derivatives of polymethylene 4 dicarboxylic acids, having more than ten carbon atoms in a normal chain the carboxylic acid groups being linked to the end carbons thereof.

2. A process for the derivatives of monocyclic ketones having more than nine ring members comprising heating cerium salts of alkyl derivatives of polymethylene dicarboxylic acids, having more than ten carbon atoms in a chain the carboxylic acid groups being linked to the end carbons thereof.

3. A process for the preparation of alkyl derivatives of monocyclic ketones having more than nine ring members, comprising heating a mixture of alkyl polymethylene dicarboxylic ,acid salts of metals belonging to the fourth group of the periodic system, these salts having more than ten carbon atoms in a normal chain the carboxylic acid groups being linked to the end carbons thereof.

4. A process for the preparation of alkyl derivatives of monocyclic ketones having more than nine ring members, comprising heating a mixture of cerium, didymium and lanthanium salts of alkyl polymethylene dicarboxylic acids having more than ten carbon atoms in a normal chain the carboxylic acid groups being linked to the end carbons thereof.

In testimony whereof I afiix my signature.

LEOPOLD RUZICKA.

preparation of alkyl normal 

